Regenerative furnace for annealing and like purposes.



A. L. STEVENS. REGENERATIVE FURNACE FOR ANNEALING AND LIKEPURPOSES. APPLICATION FILED SEPT. I0. 1912.

1,21 9,500. Patented Mar. 20, 191?.

8 SHEETS-SHEET l.

A. L. STEVENS. REGENERATIVE FURNACE FOR ANNEALING AND LIKE PURPOSES.

APPLICATION FILED SEPT-10. l9l2- 8 SHEETS-SHEET 2.

Patented Man20, 1917. (Y)

A. L. STEVENS.I REGENERATIVE FURNACE FOR ANNEKUNG AND LIKE PURPOSES.

\\ V APPLICATION men SEPT. 10. 912. m1 9,50.

t Patented Mar. 20, 1917.

A. 'L. STEVENS.

REGENERATIVE FURNACE FOR ANNEALING AND LIKE PURPOSES.

APPLICATION FILED SEPT-10. 1912.

1,21 9,500. Patented Mar. 20,1917.

8 SHEETS-SHEET 4.

A. L. STEVENS. REGENERATIVE FURNACE FOR ANNEAUNG AND LIKE PURPOSES.

' APPUCATION HLED SEPT. 10. I912. 1,Q1,50@.

Patented Mar. 20, 1917.

A. L. STEVENS.

REGENERATIVE FURNACE FOR ANNEALING AND LIKE'PURPOSES. APPLICATION FILED SEPT.-10. 19x2.

1 1 9,500. Patented Mar..20, 191?.

8 SHEETS-SHEET 6.

A. L. STEVENS. v REGENERATIVE FURNACE FOR ANNEALING AND H KE PURPOSES.

1 ,21 9;,5Uflv Patented Mar. 20, 191?. B SHEETS-SHEET 7- APPUCATION FILED SEPT. 10. 1912.

A L. STEVEN S. REGENERATIVE FURNACE FOR ANNEALING AND LIKE PURPOSES.

APPLICATION FILED SEPT-10,1912- 1 91 9,590., Patented Mar. 20, 1917 a sqgsTs-smsn a.

. curios.-

ARTHUR L.- STEVENS, or-enroaeo, ILLINOIS.

REGENERAIIVE FURNACE FOR. NEALING AND LIKE PURPOSES.

Specification of Letters Patent.

Patented Mar. 20, 191 7,.

Application filed September 10, 1912; Serial No. 719,529.

To all whom it may concern:

Be it known that I, ARTHUR L. STEVENS, a citizen of the United States, residing at Chicago,-in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Regenerative Furnaces for Annealing and like Purposes, of which the following is a'specification.

The invention relates to regenerative furnaces and particularly to furnaces for annealing -or like purposes.

One of the objects of the invention is to provide a furnace of this character which will be very compact thereby economizing floor space. decreasing cost of construction and minimizing heat losses by radiation.

A further object is to provide a furnace in which the annealing is done by radiation without direct impingement of the flame on the articles treated.

A further object is to provide certain arrangements of the fines and the instrumentalities employed for introducing the fuel into the heating chamber whereby all of the articles treated may be subjected to a uniform temperature. I

A further object is to provide a furnace which may be adapted, by making slight changes in certain structures, for the use of either gas or oil as a fuel.

A further object is to provide a furnace structure which will be very strong and durable, the construction in this respect contemplating the practical elimination of arches and an arrangement of the movable hearth whereby the weight of the hearth and the articles carried thereby-is transmitted directly. to a foundation without exerting any stress on the brick work of the furnace.

The invention has for a further object to provide certain novel constructions and devices for reversing the circulation through the regenerators and heating chamber.

The invention has for a further object to provide a furnace having the new and improved features and consisting of the novel arrangements, combinations and constructions shown in the drawings hereto annexed and which will be more fully described and claimed in the following specification.

The accompanying drawings show a preplan taken on line 33 Fig. 4, a cross-sectional view on line 4-4. of Fig. 5, looking in the dlrectlon of the ar-' rows;

Fig. 5, a longitudinal sectional view on line 55 of Fig. 4, looking in the direction of the arrows;

plan taken on" line Fig. 10 is a sectional View taken on line 1010 of Fig. 9, looking in the direction of the arrows.

Like characters of reference designate like parts in the several figures of the drawings. The furnace structure is made up of brick work preferably built upon a cement foundation 25 and supported and reinforced by a structural steel frame 26. The furnace structure consists of side walls 27, a. back wall 28 and an arched roof 29, the thrust of which latter is taken by the structural steel frame 26, the arch being supported on angle irons 30 secured to the steel frame. The front end of the furnace is open. Within the furnace are rails 31 laid on ties 32 on the cement foundation 25. A truck 33 runs on the rails 31 .and the platform 34 of this truck, which is of refractory material, forms the hearth of the furnace. The opening in the front of the furnace above the hearth is cl sed by suitable doors to which are attached cables 36 passing over sheaves 37 on the steel framing of the furnace. Any suitable mechanism may be employed for raising and lowering the doors. Seals are pro- 1 nated 38 are bridge walls 41, 41' spaced vidcd for preventing the escape of heat from the/heating chamber around the sides of the-truck, the seals consisting of troughs 39 filled with sand, into which pro ect flanges 40 on the truck. I

At the sides of the heating chamber desigaway from the side walls of the furnace so as to provide vertical combustion spaces 42,

the regenerators 43 on the other side of the.

furnace being similarly connected, one with another, by a flue 44. The regenerators of each series are separated from one another by transverse partitionwalls 45 which extend from the outer side Walls 27 of, the furnace back to the inner walls 46. Each regcnerator communicates with the combustion space, 42 or 42 as the'case may be, by a flue 47. These distributing flues are arranged in pairs,'the fines of each pair converging or being inclined one toward the other at the'top. The combustion spaces 42,

42 are each divided into a number of separatespaces orflues-by means of partition walls 48 built upon the partition walls 45.

One pair of flues 47 communicates with each of the "subdivisions of the combustion 42 42.

The side walls of the furnace are formed 'with recesses 49 which extend back under the combustion spaces between the flues of each pair of fiues 47. The brick work under the combustion spaces is formed with spaces flaring openings 50, and burners 51, 51

are located in the spaces 49 directly beneath these openings. Any suitable form of gas or oil burner might be used. I have shown oil burners such as that which forms the subject-matter of my copending application Serial No. 719,527,,filed September 10, 1912,-

but in View of the fact that burners of various types might be used in place of this:

preferred burner, it will ,not be necessary to 7 describe the latter in detail.

As stated, the furnace might beffired with gas, very slight structural changes being Ting is made in the brick work between the necessary to convert it from an oil to a gas consuming furnace The necessary changes are shown in Figs. 9 and 10. A larger openrecess 49 and the combustion space 42 and heme bricks 52 are placed crosswise of each other over this opening. The front of the recess 49 i closedup as indicated at 53 and gas is'admlttedto the recess through a nozzle 54 leading from the gasmain 55.

In order to insure a proper distribution of air passing in and out of the heating chamber through the tines 47 and thereby provide for heating the annealing chamber uniformly from one end to the other, the

several lines 47 are provided with brick dampers 56 which slide through slots in the side walls of the furnace and in grooves 57 (Fig. 5) in the brick work defining said.

flues. The dampers 7.56 may be adjusted so that the distribution of incoming air atone side of the furnace, and similarly the outgoing nroducts of combustion on the other side of the'furnace, will be emlalizcd for the several fiues. Without this equalizing means the circulation would be likely to short-circuit through one end of the furnace. r

The flucs 44, 44 extending'under the generators on opposite sidesof the furnace are connected by a 'cross'fiue 58 at iheback of the furnace. The stack 5.) leads from the middle of this flue.

A double-acting valve isarrangc'd ateach end of the cross fine 58. Each ofthese de-' vices 1s adapted at one'rclative position of its operative partsto vopen the regeneration withwhich it is associated to the atmos-. phere so that fresh air may enter same, and at the-same t me-close communication between said regenerator and the-stackyand at another relative position of said parts to close the fresh air intake and put the regenthe left hand valve in Figl 8)" designates a.

tubular element which slides through a cover plate 61 arranged over an opening 62 in the brick work 63 in which flue 58 is formed. The tubular element is provided of a rod 67 which is attached to a cable 68 passing over sheaves 69, 70, 71, '72 to the valve on the other side of the furnace. Slidably mounted in a framework 7 is a sleeve 74 through which passes the rod 67, the sleeve being threaded at its upper end for a nut 75 having, for convenience of manipulation, the hand wheel \76. ()n the emlof the sleeve is a disk. valve 77 adapted to close the openend of the tubular element 60 when thelattcr is raised. The function of nut 75 is to adiustablv position the valve 77 with respect to 'theend of the tubular element- (30 so as to var the eflective size of the air intake provided when the tubular element is in its lower position in engagement with Stat 65. As the sleeve 74 is slidable the valve 77 Will travel with the tubular element 60 if its initial position with respect to the 105 at the bottom with a valve64 adapted to tion of the valves, the reference character 60' is used to designate the tubular valve element on the other side of the furnace from the valve just described. The other parts of these two mechanisms, which are identical, are given the same reference numbers in the drawings. It will be understood that the arrangement is such that when the tubular element 60 is in its upper position the element 60 is in the lower position and vice versa.

I do not lay claim herein to the valve mechanism just described, taken by itself, as the same forms the subject matter of my copending application Serial No. 719,530, filed September 10, 1912. v

The operation of the furnace above described is as follows: Assuming the valves 60, 60 to be in the positions shown in Fig. 8, fresh air enters the regenerators 43 at one side of the furnace through the tubular valve element 60 and flue 44 and after being preheated in the regenerators (which have received heat in the previous cycle) passes into the combustion spaces 42 where it is mixed with the oil from burners 51, or gas from gas pipes 54 as the case may be. Combustiontakes place in the spaces 42, the flames being directed upwardly against the roof of the furnace. The flames are projected across the heating chamber with a reverberatory action against the roof and are drawn down by the stack draft through the combustion spaces 42, into the regenerators 43, and thence through the flue 44 to the stack 59, the Valve element 60 (at the right hand side of Fig. 8) being raised so as to put the flue 44' in communication with the cross flue 58 and close the air intake on this side of the furnace.

To equalize the temperature in the heating chamber the bridge walls are preferably formed with the-openings 78. The combustion' takes place in the upper part of the heating chamber above the bridge walls and hence there is no direct impingement of the flames upon the work on the hearth 34. The articles treated areheated by radiation. The arrangement of a number of separate regenerators at each side of the furnace tends to equalize the temperature of the incoming air and distribute the same uniformly from one end of the furnace to the other. Perfectly equalized distribution may be obtained by a proper adjustment of the dampers 56. This insures a uniform temperature in the furnace from end to end so that the articles treated are heated uniformly.

The circulation through the regenerators and through the heating chamber is reversed by raising the tubular element 60 and lowering the tubular element 60 which may be done simultaneously. Fresh air is now taken into the furnace through flue 44 and the regenerators 43. Fuel is new supplied to the furnace on this side, the supply on the other side being cut off. The draft across the heating chamber is from bridge wall 41 to bridge wall 41. The products of combustion pass down through the spaces 42 into the regenerators 43 and out through flue 44 to the stack, the valve element 60 standing aivay from its seat and being closed at the top so as to put the fine 44 in communication with the cross flue 58 and close the fresh air intake.

From the point of view of structure it will be seen that the furnace is very compact. It occupies but little floor space. This is an advantage in itself and also minimizesheat losses byradiation. The truck 33 and its load is borne directly by the. cement foundation 25. It exerts no stress against the furnace structure. The use of arches is almost entirely eliminated. The only arch is the roof arch 29 and the thrust of this arch is taken by the steel frame of the furnace. In forming the flues 44, 44. the distributing fines 47 and the regenerators, the bricks are corbeled as shown so as to avoid the use of arches. This makes the furnace structure very strong and durable.

The furnace can be readily adapted to the use of either oil or gas as a fuel, the modification in structure necessary to make the change from one fuel to the other being very slight.

While I have described my invention in certain preferred embodiments, it will be understood that modifications might be made withoutv departure from the invention. Therefore, I do not wish to be understood as limiting the invention to all of the particulars of construction and arrangements shown and described.

I claim:

1. In a furnace for annealing, or like purposes, the combination with means constituting a heating chamber, of bridge walls in said heating chamber extending above the hearth of the chamber and spaced from the sidewalls thereof soas to provide combnstion spaces, and a plurality of separate regenerators arranged under each combustion space, and fines connecting said regenerators with said combustion spaces.

3. In a furnace for annealing, or like purposes, the combination with means constituting a heating chamber, of bridge walls in said heating chamber spaced from the side walls thereof so as-to provide combustion spaces, and a plurality of separate regenerators arranged under. each combustion space, and pairs of fines leading from said regenerators to the combustion spaces, the fines of each pair inclining toward each other.

4. In a furnace for annealing, or like purposes, the combination with means constituting a heating cham u, of bridge walls in said heating chamber spaced from the side walls thereof 'so as to provide combustion spaces, and a plurality of separate regenerators arranged under each combustion space,pai'rs of fines leading from said regenerators to the comlulstion spaces, the fines of each pair inclining toward each other,

and transverse partition walls in said spaces between the pairs of fines.

5. In a furnace for annealing, or like purposes, the combination with means constituting a heating chamber, of bridge walls in said heatingchamber spaced from the side 'alls thereof so as to provide combustion spaces, a plurality of separate regenerators arranged under each combustion space, pairs of flueslw'ding from said regenerator-s to the combustion spaces, the fines of each pair inclining toward each other, and means for introducing fuel into the combustion spaces between the fines of each pair of fines.

6. In a furnace for annealing, or like purposes, the combination with means constituting a heating chamber, of bridge walls in said heating chamber extending above the hearth of the chamber and spaced from the side walls thereof so as to provide combustion spaces, a plurality of separate regenerators arrangedlengthwise of'the furnace on each side having ilucs communicating with said combustion spaces, a flue extending under and connecting together the regenerators on each side of the furnace, and means for reversing the draft through said regcnerators and heating chamber.

8. In a furnace for annealing, or llke purposes, the combinatlon with'means constituting a heating chamber, of bridge walls in said heating chamber extending above the hearth of the chamber and spaced from the side walls, thereof so as to provide combustion spaces, regenerators arranged under said combustion spaces, and distributing fines connecting the regenerators with said combustion spaces.

9. In a furnace for annealing, orlike purposes, the combination With'means constituting a heating chamber, of bridge walls in said heating chamber extending'above the hearth of the chamber and spaced from the side walls thereof so as to provide combustion spaces, regenerator-s arrangedunder said combustion spaces, distributing fines connecting the regenerators with said combustion spaces, mounted in the side valls of the furnace to equalize the inflow and outflow through said distributing fines. p

10. In a furnace for annealing,or like purposes, the combination with means constituting a heating chamber, of bridge walls in said'heating chamber extending above the hearth of the chamber and spaced from the side walls thereof so as to provide combustion spaces, regenerators arranged under said combustion spaces and communicating therewith, a fine connecting the regenerators on one side with thoseon the other, a stack opening out of said flue between the regenerators, and a valve mechanism interposed between each regenerator and the stack adapted in one position to open the air intake to the regenerator and close communication between the regenerator and the and dampers slidably stack and in another position to close said air intake and open communication between the regenerator and the stack. 11. In a furnace for annealing, or like purposes, the combination with means constituting a heating chamber, of bridge walls in said heating chamber extending above the hearth of the'chamber and spaced from the side walls thereof so as to provide combustion spaces, regenerators arranged under said combustionspaces and communicating therewith, a flue connecting theregenerators on one side with those on the other, a stack opening out of said flue between the regenerators, and a valve mechanism interposed between each regenerator and the stack adapted in one position to open the air intake to the regenerator and close communication between the regenerator and the stack and in another position to close said air'intake and open communication between the regenerator and the stack, said mechanism comprising means for varying the effective size of said air intake. l

12. In a furnace for annealing, or like 1 purposes, the combination with a foundation, of a furnace supported on the foundation open at one end, a truck adapted to enter'th'e open end of the furnace, a track for said truck supported directly on said foundation, a door closing the open end of the furnace above said. truck, bridge walls within said furnace, regcnerators arranged under the bridge walls, distributing fiues be tween the regenerators and the spaces back of the bridge walls, a line connecting the regenerators on one side of the furnace with those on the other, a stack leading from said connecting line, and valve mechanism for reversingthe circulation through said fur-1 na'c e and regencrators.

13. In a furnace for annealing or like purposes the combination with means constituting a heating chamber, of bridge walls in said heating chamber extending above the hearth of the chamber and spaced from. the

side walls thereof so as to provide combustion spaces, and flues for creating an upward draft in said spaces; said heating chamber including a roof arched across the chamber from-one of said side walls to the other. i

ll. In a furnace for annealing or like purposes the combination with means constitutiug a heating chamber, of bridge walls in said heating chamber extending above the bed of the chamber substantially half-Way to the roof thereof and spaced from the side walls thereof so as to provide combustion spaces, and flucs for creating an upward draft in said spaces; said heating chamber including a roof arched across the chamber from one of said side Walls to the other.

ARTHUR L. STEVENS. Witnesses L. A. FALKENBERG, R. O. THORESON. 

